Nowadays, magnetic elements such as inductors and transformers are widely used in many electronic devices to generate induced magnetic fluxes. Recently, since the electronic devices are developed toward minimization, the electronic components contained in the electronic products become small in size and light in weight. Therefore, the magnetic element and its conductive winding module are slim.
Take an inductor for example. FIG. 1A is a schematic exploded view of a conventional inductor. The inductor 1 principally comprises a bobbin 11, a magnetic core assembly 12 and a coil 13. The bobbin 11 has a winding section 111 for winding the coil 13 thereon. The bobbin 11 further has a channel 112 running through a center portion thereof. In addition, the bobbin 11 has several pins 113 extended from the bottom surface thereof and connected to the coil 13. By soldering the pins 113 on a circuit board (not shown), the inductor 1 is mounted on and electrically connected to the circuit board. The magnetic core assembly 12 includes a first magnetic part 121 and a second magnetic part 122. The first magnetic part 121 has a central post 121a and two side posts 121b. The second magnetic part 122 also has a central post 122a and two side posts 122b. As such, the first magnetic part 121 and the second magnetic part 122 of the magnetic core assembly 12 are cooperatively formed as an EE-type core assembly.
For assembling the inductor 1, the central post 121a of the first magnetic part 121 and the central post 122a of the second magnetic part 122 are aligned with the channel 112 and embedded into the channel 112. In addition, the side posts 121b of the first magnetic part 121 are contacted with the side posts 122b of the second magnetic part 122. As such, the coils 13 will interact with the magnetic core assembly 12 to achieve the function of inductor. The resulting structure of the assembled inductor 1 is schematically shown in FIG. 1B.
For controlling inductance of the inductor 1, the distance between the central post 121a of the first magnetic part 121 and the central post 122a of the second magnetic part 122 should be adjusted such that the air gap of the inductor 1 is changed. For achieving the purpose, portions of the central posts 121a and 122a are scraped by a tool such that central post 121a/122a is shorter than the side post 121b/122b by d0 (as shown in FIG. 1A). Under this circumstance, after the central post 121a of the first magnetic part 121 and the central post 122a of the second magnetic part 122 are embedded into the channel 112, the central post 121a is distant from the central post 122a by a gap of 2×d0. Due to the gap, the inductance of the inductor 1 is adjusted.
The process of fabricating the inductor 1 has some drawbacks. For example, since the side posts 121b and 122b are disposed at bilateral sides of the central posts 121a and 122a, the side posts 121b and 122b become hindrance from scraping the central posts 121a and 122a. Especially when a longer gap is required, the process of scraping the central posts 121a and 122a is time consuming and complicated. In addition, since the side posts 121b of the first magnetic part 121 are contacted with the side posts 122b of the second magnetic part 122, the volume of the inductor 1 is very bulky.
Therefore, there is a need of providing an improved magnetic element so as to obviate the drawbacks encountered from the prior art.